Gitlab vs S3 for configs/certs/encrypted keys and passwords/dockerfiles/docker images

I am currently torn between using S3 and our private Gitlab for storing the aforementioned items that will be used in building out a production ready private docker registry (2.0) using cloud formation for provisioning and chef to bootstrap the server.

I really want to take out the config files from S3, as well as any dockerfiles I have and start versioning them - so obviously git is perfect for that. But then I am stuck having all my certs, private keys and passwords (these are all encrypted with AWS Key Management Service, so I can really store them anywhere I want).

I would really prefer to have everything in one place. So my question is - is it a big no-no storing (even if encrypted) private keys and passwords in a private on premise git repo. Does it even make sense and/or is bad practice to store things that don't really version like passwords or tarred docker images?